package com.zack.gank.gankandroid;

/**
 * Created by Android on 2017/7/27.
 */

public class Calculator {
    public double sum(double a, double b){
        return 0;
    }

    public double substract(double a, double b){
        return 0;
    }

    public double divide(double a, double b){
        return 0;
    }

    public double multiply(double a, double b){
        return 0;
    }

}
